Not Applicable.
Not Applicable.
Not Applicable.
1. Field of the Invention
The present invention generally pertains to keyboard-operated musical instruments, and more particularly to a mounting bracket for supporting a recording sensor assembly within an acoustic piano.
2. Description of the Background Art
Acoustic pianos and similar mechanically operated musical instruments often incorporate recording sensors for registering the movement of the keys during a session in which the instrument is being played. The sequence of registered key activity may be subsequently utilized by an electronic player mechanism, in the same instrument or other instruments, to activate the keys of the instrument to substantially reproduce the music of the original session in which the key movements were registered.
Recording sensors are typically mounted either beneath the keyboard of the instrument to sense the movements associated with each key, or more preferably proximal to the action stack for sensing the movement of the hammer shanks. It will be appreciated that numerous elements of an acoustic piano are subject to movement in response to the operation of a key. Within a typical piano, for example, key operation may be sensed directly or by sensing the movement of the hammers, hammer shanks, or other parts which move in response to key operation. A separate sensor is utilized for each key to allow the actions of every key to be properly registered. It should be appreciated that modern recording sensors are capable of recording subtle keystroke nuances and can very accurately sense the position and velocity with which the keys are operated. Achieving this level of accuracy, however, requires that the sensors be positioned accurately with respect to each key with the assurance that the position of each sensor will not shift over time. To achieve sensor positioning accuracy and to simplify mounting, sensors are generally manufactured within sensor assemblies that contain a plurality of sensor elements. Each sensor assembly typically comprises a substantially flat printed circuit board upon which the sensor circuitry has been mounted. On acoustic pianos, the sensor assemblies are generally installed above the hammer shanks.
The direct mounting of sensor assemblies proximal to the action stack of an acoustic piano, without the use of a mounting bracket, can provide a compact installation, however, difficulties arise with regard to installation, adjustment, and maintenance of the associated sensor circuits. In addition, the spacing of internal structures within the instrument can differ substantially from one piano make and model to another. Therefore, a number of mounting brackets and rails have been developed by manufacturers for retaining sensor assemblies within a variety of acoustic pianos and other similar musical instruments.
One such mounting apparatus retains sensor assemblies within a mounting rail, such as a U-shaped channel. The use of mounting rails allows the position of the retained sensor assemblies to be adjusted along the length of the rail to align with the hammer shanks and then to be locked in place by inserting and engaging a separate fastener. The use of rail mounts and other typical sensor assembly mounts, requires the removal of one or more fastener elements prior to inserting, adjusting, or removing a sensor assembly.
Utilizing mounts for retaining sensor assemblies within the piano, or equivalent, can also give rise to another set of problems. In particular, a situation can arise in which the added size of a mounted sensor assembly interferes with proper hammer motion and thereby compromises the quality of instrument operation. Such a situation may arise from using a sensor assembly mount that requires more vertical spacing than exists above the hammer shanks within the instrument. For example, in the case of a mounting rail, it will be appreciated that sufficient vertical clearance is necessary for the combination of sensor assembly, the thickness of the mounting rail material, and the clearance between the mounting rail and the bottom of the sensor assembly. Furthermore, the adjustment, removal, or re-insertion of a sensor assembly within the mounting device is generally cumbersome, and typically requires the use of tools for manipulating one or more fasteners.
Therefore, a need exists for a sensor mounting apparatus that simplifies the sensor assembly mounting and adjustment process within various acoustic piano makes and models while minimizing the vertical space requirement. The present invention satisfies those needs, as well as others, and overcomes the deficiencies of previously developed recording sensor mounting apparatus.
The present invention comprises a mounting bracket for supporting a recording sensor assembly Within a keyboard-operated musical instrument, such as an acoustic piano, or similar. A sensor assembly may be readily inserted, adjusted, or removed from the mounting bracket by applying a manual force, such as to a release member, without the need to remove or install fasteners. The mounting bracket is capable of supporting a sensor assembly in approximately the same vertical space as would be required to attach the bare sensor assembly within the instrument.
The mounting bracket attaches to the action stack to support a sensor assembly on a portion of the bracket which is attached adjacent to the side of the respective hammer flanges. Since the vertical thickness of the bracket supporting the sensor assembly is positioned between the hammer flanges, as contrasted to above the hammer flanges in the case of a mounting rail, the present mounting bracket can be designed with negligible vertical space penalty. Therefore, a sensor assembly may be mounted using these brackets in approximately the same vertical space as would be required to fasten an unmounted sensor assembly to the action stack. When mounted within an acoustical piano, the portion of the bracket which supports the sensor assembly is joined to a substantially horizontal portion of the bracket that overlies the hammer flange and is adapted with an opening through which the hammer flange fastener has been received. Preferably, the mounting bracket of the present invention substantially conforms to a portion of the horizontal and vertical surfaces of the hammer flange. It is also preferable that two mounting brackets be utilized to support each sensor assembly, and that multiple mounting brackets are utilized within the piano to properly maintain the position of a number of sensor assemblies in relation to the hammer shanks, or other moving parts that are activated in response to operation of the keys. It will be appreciated, however, that the number of sensor mounting brackets utilized for supporting the sensor assemblies is a matter of choice.
A number of embodiments are described for the present invention which provide mechanisms for retaining a sensor assembly within a bracket which is designed to occupy a minimum amount of vertical space. One group of embodiments within the present invention support the sensor assembly with a locking mechanism that is configured with a release member. A sensor assembly may be received, adjusted, or removed from the mounting bracket by applying a sufficient urging force in a substantially predetermined direction to said release member. Preferably, the release member may be activated by using the fingers or thumb, to apply pressure in the correct direction on the release member to disengage a locking mechanism. Upon releasing pressure on the release member, the locking mechanism supplies a biasing engagement force to engage the sensor assembly and thereby lock its position within the mounting bracket. Another embodiment utilizes the characteristics of the sensor board itself to effect retention within the mounting bracket. Shown by way of example is a mounting bracket in which the flexure of the sensor assembly itself during receipt within the mounting bracket provides a biasing force to prevent vibration of the sensor assembly while aiding retention of the assembly within the bracket.
The releasable locking mechanism described within the first set of embodiments of the present invention is shown, by way of example, comprising a combination of a fixed retention member and a biasing retention member. The biasing retention member operating to lock the position of the sensor board within the mounting bracket. Prior to engagement of the biasing retention member, the fixed retention member acts as a limiter on vertical and longitudinal sensor assembly motion while not restricting lateral motion of the sensor assembly. When released and allowed to exert a bias force, the biasing engagement member applies retention pressure to the sensor assembly against the fixed retention member to lock the sensor assembly in a fixed position. It will be appreciated that the biasing retention member may be alternately adapted to exert an extension force in relation to a fixed retention member which engages a portion of the sensor assembly in an opposing direction.
To simplify the insertion, alignment, and positioning of the sensor assembly, a separate keyed retention mechanism is preferably incorporated within the mounting bracket. The keyed retention mechanism operates in combination with the locking mechanism. The keyed retention mechanism engages the sensor assembly to prevent the sensor assembly from shifting in a longitudinal direction which is parallel to the length of the hammer shanks. The keyed retention mechanism may also be configured so as not to be fully insertable within the sensor assembly such that the sensor assembly needs to be flexed for engagement within the mounting bracket.
It should be appreciated that more than two retention members may be incorporated per each mounting bracket without departing from the present invention. The locking retention mechanism, preferably in combination with the keyed retention mechanism, therefore operates to maintain sensor assembly position at a fixed location within the instrument to which it is attached so that positional adjustment, insertion, and removal of the sensor assemblies is readily achieved.
An object of the invention is to provide low-profile mounting of sensor assemblies proximal to the hammer shanks within an acoustic piano.
Another object of the invention is to provide a mounting bracket that allows for accurate alignment and secure positioning of recording sensor assemblies in relation to the hammer shanks, or other moving parts associated with the key operation within an acoustic piano.
Another object of the invention is to provide a mounting bracket that may be utilized with a variety of acoustic piano makes and models without compromising the instrument operation.
Another object of the invention is to provide a bracket for mounting sensor assemblies wherein multiple brackets may be compatibly utilized per instrument and/or sensor board without interfering with one another.
Another object of the invention is to provide a mounting bracket that is capable of retaining the sensor assembly in a fixed location that is substantially immune to instrument vibration.
Another object of the invention is to provide a mounting bracket that may be readily attached, or removed, from an instrument.
Another object of the invention is to provide a mounting bracket that securely retains a sensor assembly and prevents inadvertent shifting.
Another object of the invention is to provide a mounting bracket that is capable of retaining a sensor assembly without the need of separate fasteners, such as threadable fasteners, wherein the sensor assembly can be more readily inserted and removed for maintenance and repairs.
Another object of the invention is to provide a mounting bracket from which sensor assemblies may be adjusted, removed, or inserted in response to a simple one-touch manual operation by the technician.
Another object of the invention is to provide a bracket design that is reliable and may be manufactured at low cost.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.